Plotting the Way Up

When he was training in mid-1965 as pilot for
Gemini V, Conrad learned of a plan to fly Gemini around the Moon in a
mission called LEO for Large Earth Orbit. The concept, in one form or another,
had recurred sporadically (only to be scotched) ever since Gemini's first year.
But LEO raised interest all the way from MSC to Congress. NASA's top leaders,
James Webb and Robert Seamans, did not agree, contending that Apollo did not
need a competitor. If Congress wanted to appropriate additional funds, Webb
said, it would be better to spend them on the program that was designed to go to
the Moon. Another idea that flourished briefly during 1965 was a possible
rendezvous with a Pegasus satellite that was first considered for Gemini
VI, then for Gemini VIII. When extravehicular activity (EVA) was
canceled on Gemini V,VI, and VII, the planners realized
that experience would be too limited and risks too great to have an astronaut
approach a satellite in space. GPO decided in January 1966 that there would be
no rendezvous with a Pegasus.

Conrad was much taken with the notion of a Gemini trip around the Moon.5
Even after Webb dismissed the scheme, he still wanted to take Gemini as far as
it would go. When he was named as command pilot, he recalled, "it didn't look
like . . . [a high altitude] flight was ever going to get done on Gemini."
Conrad saw a heaven-sent opportunity to resurrect the idea when he calculated
that he could save some of the Agena's fuel to power a high ride.

He began a small crusade to convince NASA management that there were good
reasons for going really high. Although the Weather Bureau had satellites flying
at very high altitudes, their televised pictures of cloud formations had poor
resolution. [355] Moreover, the Bureau had been debating the use of a color
system. Conrad argued that Gemini XI could bring back films to help them decide
its worth. It was, in fact, to the experimenters that he first turned in his
campaign to fly high, asking which experiments might be helped and which
degraded by higher altitudes. He learned that Maurice M. Shapiro of the Naval
Research Laboratory was concerned that radiation particles from the Van Allen
belts might affect his nuclear emulsion experiment at the higher orbit. That
almost killed Conrad's plan before it was well started. But he enlisted fellow
astronaut Anders, a nuclear engineer, for a trip to Washington to argue against
the threat. After Anders got friends at Goddard Space Flight Center to look into
the radiation belt hazards and to devise ways of avoiding them, the high apogee
excursion soon became part of Gemini XI.6

Another unique objective for XI, direct (first orbit) rendezvous, had been
suggested before Gemini flights began. Proposed by Richard R. Carley of GPO, the
idea had been put aside when interest had focused on a concentric, fourth-orbit
plan. Carley's proposal revived when the Apollo office insisted on a closer
simulation of lunar orbit rendezvous. With some signs of reluctance, GPO asked
McDonnell to study the maneuver. The first meeting to phrase plans and ground
rules for the study revealed some foot-dragging; its results included a curious
stipulation: "There should be no artificial restrictions in the plan to make the
mission simulate Apollo operations or to simulate lunar rendezvous
conditions."7
That position was soon reversed as Apollo interests prevailed. The first change
in the flight plan to include direct rendezvous made any launch delay a reason
or shifting the mission to "a modified M = 3 [rendezvous in the third orbit]
plan," but the following version "recycled [the launch] to the next direct
rendezvous launch opportunity."8

Although schemes for achieving artificial gravity in space preceded real
manned space flight by many decades, Gemini offered the first chance to turn
science fiction into fact. Half the program had passed, however, before NASA got
around to planning tethered vehicle flights. GPO first asked the Engineering and
Development Directorate to study the problems involved in tying the Gemini
spacecraft to either the Agena or the Pegasus satellite.9
Its backlog of Apollo work forced the directorate to decline its aid, in view of
the extensive simulation required. Appeals to Flight Operations were more
fruitful, however, leading to a number of tether simulations, the data from
which were duly passed along to McDonnell.10

McDonnell's guidance and control group found that nylon or dacron tethers no
longer than 50 meters and a spin rate no more than ten degrees per second
produced a reasonable amount of cable tension and recommended that the pilots
practice spinning on a vehicle simulator to learn how best to conserve fuel.11

[356] When NASA planners listed tethered flight as a mission objective, they
first thought of it as a way of evaluating the tether as an aid to
stationkeeping;12
but it might also be a means of inducing some degree of artificial gravity. The
minimum spin rate depended on whether the tethered activity was intended
primarily for formation flying or for achieving gravity. NASA decided to try for
both, although it would settle for "an economical and feasible method of
long-term, unattended station keeping," and chose a 36-meter dacron line.13

The Gemini Mission Review Board reviewed all these new activities in depth,
especially the first-orbit rendezvous, which might be a heavy fuel user.14
Young and Collins had expended so much fuel in the Gemini X rendezvous
that the board was dubious about trying a first-orbit linkup, largely computed
onboard, with an Agena target. But Flight Director Glynn Lunney assured the
group that Mission Control could give the crew backup data on orbital insertion
and on the accuracy of their first maneuver; the network would have plenty of
information to help them begin the terminal phase of rendezvous. The board
concluded that if the rendezvous used only half the fuel supply, about 187
kilograms, there would be ample for the rest of the mission. Some skeptics
remained; William Schneider, Deputy Director for Mission Operations, bet board
chairman James Elms a dollar that it could not be done that economically.15

The board seemed less concerned about the high apogee maneuver and the
tethered vehicle exercise than about direct rendezvous. Radiation levels on
Gemini X having been only a tenth of the preflight estimate, the board
simply asked that MSC and Goddard keep track of the latest measurements. The
only major question about the tether plan was the method for freeing the
spacecraft from the Agena. The board was told that the plan was to fire a
pyrotechnic charge, ejecting the docking bar at right angles to the spacecraft
path. If that did not work, there was a break link in the tether that could be
snapped by a small separation velocity.16

As might be expected, extravehicular activity received special attention.
After the experience on Gemini IX-A, training methods were sought that
would more closely approximate flight conditions. One likely approach simulated
zero-g by putting a space-suited subject under water, where buoyancy almost
balanced weight, and leaving him to cope with mass and inertia just as he would
have to do in space.17
Despite the degree of EVA success that Collins had in Gemini X, work on
this idea went ahead. There were, as MSC Director Robert Gilruth later said,
"many mixed emotions here at the Center - some of our people didn't think the
neutral buoyancy work was any good." But Cernan, who checked out the method at
Gilruth's request, found that moving about under water in a pressure suit
closely matched his efforts in space. These findings, however, were not
impressed upon Gordon in his training for Gemini XI.18

[357] More was needed than a better training medium. Both equipment and body
positioning aids had to be improved. Hardware changes included handholds on the
target vehicle docking cone, a shorter umbilical, and better foot restraints in
the spacecraft adapter. The handholds were simple to design and install. Both
Collins and Young had complained about the 15-meter snake that had entangled
Collins. They suggested its length be cut to 9 meters, and GPO agreed.
Developing better foot restraints took a little more time. McDonnell was working
on two kinds - a spring clamp like those on a ski and a bucket type. NASA chose
the latter, which were nicknamed "the golden slippers."19

Twelve experiments were included in the Gemini XI flight plan (see Appendix
D). Nine were scientific; the other three technological. Two of the science
experiments - S-29, Earth-Moon libration region photography, and S-30, dim light
photography/orthicon were new to Gemini. The other seven - weather, terrain, and
airglow horizon photography; radiation and zero-g effects; ion-wake measurement;
nuclear emulsion; and the ultraviolet astronomical camera - and all three
technological experiments - mass determination, night image intensification, and
power tool evaluation - had been assigned to previous missions. The Gemini
Mission Review Board concluded that they fitted properly into the Gemini XI
workload. By 25 August, MSC was able to report that all experiments were ready
for flight.20

When reduced launch intervals required faster delivery to the Cape, the
challenge was met. Before the end of July, launch preparations were under way in
Florida. On 11 August, NASA announced that the flight would be launched on or
about 9 September, only two days after the target date set more than three
months earlier.21

The countdown-to-launch began on schedule on 9 September 1966, but it did not
finish that way. After the booster was fueled, the launch crew detected a
pinhole leak in the first stage oxidizer tank, which had to be fixed.
Technicians used a sodium silicate solution and an aluminum patch to plug the
leak; and Mission Director Schneider reset the launch for 10 September.

Trouble for the second scheduled send-off cropped up in a different area and
much later in the countdown. Conrad and Gordon had completed the required
rituals and headed toward pad 19 and their spacecraft when they heard that the
Atlas, only 1,800 meters away, was having a problem with its autopilot. The
General Dynamics test conductor called a hold in the countdown to have this
suddenly wayward instrument checked. His engineers told him they were receiving
faulty readings and were running checks before deciding whether to replace the
part. When the delay had stretched to an hour, Schneider postponed the launch
for two more days. The problem was caused by a combination of factors - a
fluttering valve, unusually high winds, and a too-sensitive telemetry recorder -
none of which required replacement of the autopilot. There would be no further
delay.22